Base excision repair capacity as a determinant of prognosis and therapy response in colon cancer patients.
DNA Repair (Amst)
; 72: 77-85, 2018 12.
Article
in En
| MEDLINE
| ID: mdl-30314738
ABSTRACT
The DNA-damaging agent 5-fluorouracil represents the most commonly used chemotherapeutic drug for colorectal cancer patients. DNA lesions associated with 5-fluorouracil therapy are primarily repaired by base excision repair (BER) and mismatch repair (MMR) pathways. Published evidence suggests that the individual DNA repair capacity (DRC) may affect a patient's prognosis and response to chemotherapy. With this in mind, we designed a prospective study of which the main aim was to investigate BER-DRC in relation to 5-fluorouracil response as potential predictive and/or prognostic biomarker. BER-DRC was supplemented by a microsatellite instability (MSI) analysis which represents an indirect marker of MMR activity in the tumor. All parameters were measured in paired samples of tumor tissue and non-malignant adjacent mucosa of 123 incident colon cancer patients. Our results indicate that BER-DRC in non-malignant adjacent mucosa was positively associated with overall survival (P = 0.007) and relapse-free survival (P = 0.04). Additionally, in multivariate analysis, good therapy responders in TNM stage II and III with an elevated BER-DRC in mucosa exhibited better overall survival. Moreover, the overall survival of these patients was even better in the presence of a decreased BER-DRC in tumor tissue. The ratio of BER-DRC in tumor tissue over BER-DRC in mucosa positively correlated with advanced tumor stage (P = 0.003). With respect to MSI, we observed that MSI-high tumors were mostly localized in proximal colon; however, in our cohort, the MSI status affected neither patients' prognosis nor survival. In summary, the results of the present study suggest that the level of BER-DRC is associated with patients' survival. BER-DRC represents a potential prognostic biomarker, applicable for prediction of therapy response and useful for individual approach to patients.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Colonic Neoplasms
/
DNA Repair
Type of study:
Diagnostic_studies
/
Observational_studies
/
Prognostic_studies
/
Risk_factors_studies
Limits:
Female
/
Humans
/
Male
/
Middle aged
Language:
En
Journal:
DNA Repair (Amst)
Journal subject:
BIOLOGIA MOLECULAR
/
BIOQUIMICA
Year:
2018
Document type:
Article